Method of and apparatus for anchoring well-drilling platforms to the ocean floor



March 31, 1970 M. E. KLIEWER METHOD OF AND APPARATUS FOR ANCHORING WELL-DRILLING PLATFORMS TO THE OCEAN FLOOR 4 Sheets-Sheet 1 Filed March 7, 1968 amM/ I IN VE/VTOI? Max E. Kuswse March 31, 1970 M. E. KLIEWER 3,

METHOD OF AND APPARATUS FOR ANCHORING WELL-DRILLING PLATFORMS TO THE OCEAN FLOOR Filed March 7, 1968 4 Sheets-Sheet 2- li ra 5'. L 10 4'.

29 2 9 22a 51 2 1 I a A, 25 250.. 25 A re IO I2 f/vvslvroe. 15a Max E. Kuswe'e March 31, 1970 v M. E. KLIEWER 3,503,217

METHOD OF AND APPARATUS FOR ANCHORING WELL-DRILLING PLATFORMS TO THE OCEAN FLOOR Filed March 7, 1968 4 Sheets-Sheet 5 IN VEN 7-02 Max KL/EWER March 31, 1970 M. E. KLIEWER 3,503,217

METHOD OF AND APPARATUS FOR ANCHORING WELL-DRILLING PLATFORMS To THE OCEAN FLOOR 4 Sheets-Sheet 4 Filed March 7, 1968 ER m vim .Z'NvE/vroe. Max E. KL/EWEE United States Patent 3,503,217 METHOD OF AND APPARATUS FOR ANCHORING WELL-DRILLING PLATFORMS TO THE OCEAN FLOOR Max E. Kliewer, Whittier, Calif., assignor to Baker Oil Tools, Inc., Commerce, Calif., a corporation of California Filed Mar. 7, 1968, Ser. No. 711,249 Int. Cl. E21b 40/00, 23/00; E02!) 17/00 US. Cl. 6146.5 17 Claims ABSTRACT OF THE DISCLOSURE A method of anchoring a well-drilling platform to the ocean floor by running lengths of pipe or piles through outer pipes attached to platform legs and into holes formed in the ocean floor. The lengths of pipe or piles are cemented in the holes, and are also connected to the outer pipes by cementing the annuli between the outer pipes and such piles. Apparatus is provided for supporting or anchoring the piles in the outer pipes, for enabling the cementing of the piles in the holes, and for cementing the annuli between the outer pipes and the piles.

In the drilling of wells, such has oil or gas wells, into or through the fioor of an ocean or other body of water, a drilling platform is provided that is bottomed on the ocean floor, the drilling of one or more wells, as well as the production of such wells, being conducted from the top of the platform above the surface of the water.

Anchorage of such platforms to the ocean floor poses problems due to ocean currents, wave action, wind, and the like, particularly in the case of platforms which are to be anchored to ocean floors in waters of substantial depth, for example, on the order of 500 to 600 feet below the water surface. Piles may be connected to the legs of such platforms for anchoring them to or in the ocean floor, the piles being cemented in place.

The present invention provides a method of anchoring well-drilling platforms to the ocean floor in such a manner that the platform is sturdily based and can support large loads vertically, as well as resist lateral forces caused by subsea currents, waves and wind. More specifically, the invention provides such a method wherein lengths of pipe or piles are anchored firmly in holes formed, as by drilling, into the ocean floor, such lengths of pipe or piles also being anchored firmly to the legs of the platform.

An object of the invention is to provide a method of anchoring well-drillin g platforms to the ocean-floor, wherein the platform legs are provided with a number of large supporting pipes thereabout, and smaller diameter lengths of pipe or casing, constituting piles, are run partially through such supporting pipes and into holes drilled in the ocean floor, the lengths of smaller diameter pipe or piles then being both secured within the outer supporting pipes and cemented in the drilled holes. Within the purview of this objective, the lengths of pipe or piles may be mechanically anchored in the outer supporting pipes, or cemented therein, or both.

The invention also provides apparatus useful in the practice of the method hereof. More specifically, the invention provides such apparatus in which the lengths of pipe or piles are run into the drilled holes in the ocean floor on a string of running-in pipe or drill pipe, through which the cementing of the lengths of pipe or piles is ac- 3,503,217 Patented Mar. 31, 1970 ice complished. The apparatus includes an upper stage cementing collar, whereby the length of each pipe or pile may be cemented in the hole drilled in the ocean floor in one stage, and the annular space between such lengths of pipe or pile may be cemented through the stage cementing in another cementing stage to securely integrate and anchor the structure to the ocean floor.

The apparatus also includes anchor means whereby the lengths of pipe or piles may be securely mechanically anchored within the outer supporting pipes of the platform legs prior to cementing.

This invention possesses many other advantages and has other objects which may be made more clearly apparent from a consideration of several forms and methods embodying the invention. These for-ms and methods are shown and described in the present specification and in the drawings accompanying and constituting a part thereof. They will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a view in elevation showing an offshore well drilling platform anchored to the fioor of a body of water;

FIG. 2 is a detail view of a typical pile structure for the legs of the platform of FIG. 1;

FIG. 3 is a fragmentary longitudinal sectional view, illustrating one form of apparatus for supporting the pile in the outer pipe and enabling the pile to be cemented in stages in the drilled hole and within the outer pipe, the apparatus being shown in condition for running the pile into the outer pipe;

FIG. 4 is a view corresponding to FIG. 3, disclosing the pile supporting anchor set in the outer pipe and the lower or first stage cementing operation completed;

FIG. 5 is a view corresponding to FIGS. 3 and 4 illustrating the upper or second stage cementing operation;

FIG. 6 is a combined elevational and longitudinal sectional view disclosing another form of apparatus for supporting the pile in the outer pipe, with the lower or first stage cementing operation completed;

FIG. 7 is a view corresponding to FIG. 6, but showing the second stage cementing operation; and

FIG. 8 is a cross-section taken along the line 88 on FIG. 1.

Referring first to FIG. 1, the present invention involves the problem of anchoring a drilling platform P to the floor F of the ocean or other body of water W, from which the usual welLdrilling, completion, and production operations may be performed. In the illustration, the platform includes a table or deck 1 having a derrick D thereon, from which drilling and other operations may be conducted in the usual manner. The platform P includes legs 2 extending from the deck 1 downwardly through the water W to the ocean floor F, these legs 2 being suitably reinforced and interconnected by stringers and braces 3. In order to more firmly anchor the legs 2 to the ocean floor F, their lower portions are secured by interconnecting struts 4a to pile sleeves or outer pipes 4 extending below the legs and spaced circumferentially therearound.

Initially, the platform P is lowered into engagement with the ocean floor, the pile sleeves or outer pipes 4, and the legs themselves, settling into the floor F due to the platform weight, until the platform comes to rest with its deck 1 in a horizontal position. A hole 6 is then drilled through each outer pipe 4 into the ocean floor to a desired depth, which, for example, may be 100 feet, and a pile lowered into the hole in overlapping relation to the pipe 4 and cemented in place, as will later be described.

An exemplary pile structure, including a sleeve or outer pipe 4 and an inner pipe or pile 5, is illustrated in FIG. 2. In accordance with the invention, the pile 5 has been anchored or hung in the pile sleeve or outer pipe 4 by an anchor mechanism A, hereinafter to be described; the pile 5 has been cemented in the drilled hole 6, as indicated at C1; and the pile 5 has also been cemented in the outer pipe 4, as indicated at C2, all in accordance with the method and employing one form of apparatus of the present disclosure.

Referring to FIGS. 36, the apparatus of FIG. 2 and its use in the practice of the method of the invention will be described in greater detail. The pile Sis run into the outer pipe 4 on a running-in string of pipe S, such as the usual well drill pipe or tubing, extending from the derrick D downwardly into the hole 6. The lower end of the pile 5 is constituted as a cementing shoe 7 of the type employed in the cementing of well casings in well bores, the shoe 7 including an outer supporting body 8 welded or otherwise attached to the pile 5, as at 8a, an inner sleeve 9 being supported in the body 8 by an intervening cement body 10. Below the sleeve 9 is a back flow preventing means, including a ball 11 and a downwardly facing seat 12, which will permit downward flow only through the sleeve 9 and through a central passage 13 in the shoe opening into the hole 6.

In order to run the pile 5 into the hole 6 through the outer pipe 4, the shoe 7 is connected to the running-in string of pipe S by means of a threaded (preferably left hand) or other releasable connection 14. A sealing nipple 15 forms the lower portion of the pipe S, having suitable seal 15a thereon engageable within the sleeve 9 of the shoe 7, the nipple also having a central passage 15b therethrough.

Suitably made a part of the pile or inner pipe 5, as by welding at 16, is a tubular body 17 of the anchor assembly A having a lower flange or abutment 18. Spaced above the flange 18 is a downwardly facing cone or expander member 19 initially fastened to the body 17 by shear screws 20. Spaced above the expander 19 is an upwardly facing cone or expander member 21 initially fastened to the body 17 by shear screws 22, resilient means, such as coiled springs 23, being interposed between the expanders 19 and 21.

Initially secured to the expander 19 by shearable screws 24 are laterally expansible slips 25 having the pipe engaging teeth or wickers 25a thereon facing downwardly to resist downward movement when wedged into engagement with the outer pipe 4 by the cone 19, as herein,- after to be described. A set of upper slips 26 is provided having upwardly holding teeth or wickers 26a engageable with the pipe 4 upon lateral expansion of the slips 26 by the expander 21, as hereinafter to be described. These upper slips 26 are supported so as to be normally retracted on flexible or spring arms 27 depending in circumferentially spaced relation from a supporting ring 28. This ring 28 has a plurality of angularly spaced bow springs 29 extending outwardly for resilient and frictional engagement with the inner wall of the outer pipe 4, to provide friction means for holding the slips 26 against movement in the pipe 4 when the slips 26 are to be expanded. Control means are provided, comprising an inverted J slot 30 in the upper portion of the body 17 and a pin 31 projecting from the slip supporting ring 28 into the slot 30. This control means functions to hold the ring 28, and thus the slips 26, in upwardly spaced relation to the expander 21 until it is desired to set the 4 anchor A by manipulation of the running-in string S, as well be hereinafter more fully described.

At its upper end, the body 17 of the anchor assembly A is suitably connected to a suitable stage cementing collar assembly C. In the illustrative embodiment, it includes an outer tubular support or body 32 welded at 33, or otherwise secured, to the anchor body 17. Inwardly of the collar body 32 is a seal sleeve 34, there being an intervening annular body of cement 32a or other drillable material. The sleeve 34 has an inner cylindrical wall forming a bore 35 larger in diameter than the sealing nipple 15 and seal 15a previously described, so that the running-in string S and the nipple may be removed, following the completion of the first stage cementing operation, as will be further described hereinafter. Suitable sealing means are provided about the collar body 32, including an outwardly projecting flange 36 having an upwardly facing lip seal ring 37 sealingly engageable with the wall of the outer pipe or pile sleeve 4. This seal ring is herein shown as an upwardly facing rubber or other elastometric cup, adapted to prevent the downward flow of fluid therepast, but adapted to flex upwardly to facilitate running of the assembly through the pipe 4.

A number of laterally extended passages 38 lead from the bore 35 of the collar C to the outside of the outer body 32 at a location above the seal ring 37. In each of the passages 38 is a back flow preventing valve means, including a ball valve 39 engageable with a seat 40, to permit, during the second stage of cementing hereinafter to be described, fluent cement slurry to pass outwardly through each of the passages 38, but preventing its return flow through each passage 38.

The pile or pipe 5 extends upwardly from the stage collar C, being connected thereto at 41 by suitable means, such as welding. As seen in FIGS. 1 and 2, the pile may be of such length as to extend upwardly above the upper end of its pile sleeve 4.

Referring now to FIG. 4, the assemblage of FIG. 3 is shown with the pile 5 supported in the pile sleeve 4 by the anchor A, and the first stage of cementing has been completed.

In accomplishing the step of supporting the pile 5 in the pile sleeve 4, the pile is run into the sleeve 4 on the pipe string S until the shoe 7 is adjacent to the bottom of the hole 6, or until the anchor assembly A is located near the lower end of the pile sleeve 4 (FIG. 3). Thereupon, the pipe string S is rotated to move the control pin 31 in the inverted I slot 30 to a position at which it may move longitudinally in the I slot, so that the anchor body 17 may be lifted relative to the slips 26 which are held stationary by the drag springs 29. Such upward movement of the body 17 causes engagement .of the upper expander 21 with slips 26 to force the latter outwardly into anchoring engagement with the pipe 4, further upward movement of the body 17 then causing the screws 22 to be sheared. Following shearing of the screws 22, further upward movement of the body 17 will move the lower slips 25 and expander 19 upwardly, until the cone 19 compresses the springs 23 and engages the anchored upper cone 21, the screws 20 connecting the cone 19 to the body 17 then being sheared as the body 17 continues its upward movement. The flange 18 of the body 17 engages the lower slips 25, forcing them upwardly to shear the screws 24 securing the slips 25 to the expander 19 and sliding the slips 25 along the expander 19 and into engagement with the pile 4. Further upward movement of the body 17 and the pipe string S will thus be prevented, indicating at the platform, by increased load on the hoist mechanism, that the anchor has been conditioned to be set responsive to subsequent lowering of the pipe string S.

The result of such lowering of the pipe string S is shown in FIG. 4, wherein it is seen that a shoulder 22a on the body 17 has engaged the upper cone 21, forcing the lower cone 19 downwardly and urging the lower slips 25 further outwardly into anchoring engagement with the pipe 4, thereby hanging the pile 5 in the sleeve or pipe 4 and in the hole 6, with the shoe 7 spaced at least slightly above the bottom of the hole.

In the usual manner of cementing wells, a volume of fluent cement slurry is pumped downwardly through the pipe string S, passing through the passage b of the sealing nipple 15 and through the end passage 13, then flowing upwardly in the annular space R defined between the pile 5 and the wall of the hole 6. As seen in FIG. 4, this cement may enter the lower end of the pipe 4, filling the spaces therein defined by the anchor A, and, in practice, a certain amount of such cement may pass upwardly past the seal ring 37 of the stage collar C. In addition, any voids betwen the pile sleeve 4 and the earth formation may be filled with cement, if such voids exist and communicate with the hole 6.

The releasable connection or thread at 14, which connects the running-in string to the shoe 7, is relased and the pipe string S pulled from the pile 5 by the surface hoist mechanism, the sealing nipple 15 passing upwardly through the bore 35 of the stage collar C. The pile 5, in accordance with the invention, is thus anchored in the sleeve 4 and cemented in the hole 6. If no further cementing operations are desired, i.e., cementing of the entire annular T between the pile 5 and the sleeve 4 in a second stage cementing operation, the cement will be allowed sufficient time to set up.

However, if the stage collar C is to be used in performing such a second stage cementing operation, another pipe string S2 is run into the pile 5. This pipe string S2, as seen in FIG. 5, is provided with a sealing nipple 49 of the usual type having sealing means 49a adapted to sealingly engage in the bore 35 of the stage collar C, and having passage means or ports 51 adapted to communicate with the lateral passages 38 of the collar C, so as to establish communication between the passages 38 and a blind bore 52 in the nipple 50, the bore 52 opening into the pipe string S2 thereabove. When the sealing nipple 50 is thus positioned, the second stage of cement slurry is displaced down the pipe string S2, through the stage collar passages 38, into the annulus T outside the pile 5, above the seal ring 37, flowing upwardly in the annulus to fill the same to the extent desired or necessary. Thereafter, the pipe string S2 may be pulled and elevated to the deck 1.

The foregoing staged cementing operations, whereby the annulus between the pile 5 and the wall of the hole 6 is cemented by one cementing stage at C1, and the annulus between the pile 5 and the pile sleeve 4 is cemented in another stage at C2, may also be accomplished using the modified apparatus of FIGS. 6 and 7.

In this modified construction, the lower end of the pile sleeve 4 has a landing or stop collar 104 suitably connected thereto as by welding at 10411:. This collar 104 includes an inwardly extending flange 105 providing an axial opening 106 larger in diameter than the pile 5 and the shoe 7 to enable running the same through the flange 105. However, this opening 106 is smaller than the flange 36 of the stage collar C. Thus, the flange 36 will land on the landing flange 105 to support or hang the pile 5 in the pile sleeve 4. If desired in this embodiment, the contacting faces 107 and 108 of the collar flange 36 and the landing flange 105 may be provided with seal means, such as a seal ring 109, to prevent the passage of cement into the space between the pile sleeve 4 and the pile 5 above the seal ring 109. Thus, flow of cement into any channels or voids between the pile sleeve 4 and the hole above the drilled hole 6 is assured.

As will now be understood, the pile 5, in FIGS. 6 and 7, will be run into the pile sleeve 4 and into the hole 6 on the running-in string S, the shoe 7 being connected to the sealing nipple 15 by the releasable connection 14. After the pile has been landed, by engagement of the stage collar flange 36 with the landing flange 105, the

first stage of cementing may be performed. Cement will pass the back flow preventing ball 11 and will flow upwardly in the annulus R between the pile 5 and the wall of the hole 6, at C1. In addition, cement flowing further upwardly about the exterior of the pipe sleeve 4 will fill any channels or voids.

Thereupon, the pipe string S will be manipulated to release its connection 4 with the shoe 7, and the string S pulled to the deck 1. The second stage pipe string S2 will then be run in the pipe 5 and stabbed into the stage collar C (FIG. 7), the passage means 51 of the sealing nipple 50 providing for communication through the passages 38 between the interior of the pipe string S2 and the annulus T between the pile 5 and the pile sleeve 4, so that the second stage cement may be placed in such annulus at C2. The pipe string S2 is then removed.

It will now be understood that the present invention provides not only the various combinations of apparatus described above, but also the method of cementing piles in holes below the pile sleeves and in the pile sleeves themselves. When the cement sets and hardens, the offshore well-drilling platform P is securely anchored in the floor F of the ocean, or other body of water, in a simple and effective manner.

I claim:

1. In the method of anchoring a platform to the ocean floor, the platform having legs extending to the ocean floor and provided with a number of supporting pipes affixed to the legs, holes being drilled into the ocean floor below and in alignment with supporting pipes, the steps of: running piles into the supporting pipes and drilled holes on a running-in string of pipe, supporting the piles on the outer pipes against downward movement and within the outer pipes and drilled holes, placing cement in the annular spaces between the piles and the walls of the drilled holes, and removing the running-in string.

2. The method as defined in claim 1, including placing cement in the annular spaces between the outer pipes and piles.

3. The method as defined in claim 1, including placing cement in the annular spaces between the outer pipes and piles from substantially the lower ends of the outer pipes to their upper ends.

4. In the method of anchoring a platform to the ocean floor, the platform having legs extending to the ocean floor and provided with a number of supporting pipes aflixed to the legs, holes being drilled into the ocean floor below and in alignment with supporting pipes, the steps of: running piles into the supporting pipes and drilled holes on a running-in string of pipe, supporting the piles within the outer pipes and drilled holes, placing cement in the annular spaces between the piles and the walls of the drilled holes, and removing the running-in string, in which the piles are hung from the outer pipes.

5. In the method of anchoring a platform to the ocean floor, the platform having legs extending to the ocean floor and provided with a number of supporting pipes affixed to the legs, holes being drilled into the ocean floor below and in alignment with supporting pipes, the steps of: running piles into the supporting pipes and drilled holes on a running-in string of pipe, supporting the piles within the outer pipes and drilled holes, placing cement in the annular spaces between the piles and the walls of the drilled holes, and removing the running-in string, including the step of, in advance of running each of the piles, installing on the pile an anchor operable to support the pile in the outer pipe in response to manipulation of the running-in string, and, following the running of the pile, manipulating the running-in string to set the anchor whereby to anchor the pile within the outer pipe in advance of cementing the pile in said drilled hole.

6. In the method of anchoring a platform on the ocean floor, the platform having legs extending to the ocean floor and provided with a number of supporting outer pipes affixed to the legs, and holes being drilled into the ocean floor below and in alignment with the supporting pipes, the steps of: securing a cementing fitting to the lower portion of a tubular pile, connecting the fitting and its supporting pile to a string of running-in pipe, lowering a pile on the running-in string into a supporting pipe and its associated hole, supporting the pile partially in the supporting pipe and the hole therebeneath, cementing the pile in the hole by displacing cement downwardly through the running-in string and through the fitting into the annular space between the pile .and the wall of the hole, disconnecting the running-in string from the fitting, pulling said running-in string.

7. The method as defined in claim 6, including the step of cementing the annular space between the pile and the outer pipe following removal of the running-in string from the shoe.

8. In the method of anchoring a platform on the ocean floor, the platform having legs extending to the ocean floor and provided with a number of supporting outer pipes affixed to the legs, and holes being drilled into the ocean floor below and in alignment with the supporting pipes, the steps of: installing a cementing shoe in the lower end of a tubular pile, connecting the shoe and its supporting pile to a string of running-in pipe, lowering a pile on the running-in string into a supporting pipe and its associated hole, supporting the pile partially in the supporting pipe and the hole therebeneath, cementing the pile in the hole by displacing cement downwardly through the running-in string and through the shoe into the annular space between the pile and the wall of the hole, disconnecting the running-in string from the shoe, pulling said running-in string, including the steps of installing a stage cementing collar in each pile above its shoe, supporting the pile in the outer pipe with the stage collar of the pile disposed in the outer pipe, and, following removal of the running-in string of pipe, running into the pile a second string of pipe, engaging the stage collar with the second string of pipe, discplacing cement through the second string of pipe and the stage collar into the annulus between the pile and the outer pipe, and then removing the second string of pipe.

9. In apparatus for anchoring a platform on the ocean floor, the platform having legs engaged with the ocean floor, and a number of pile sleeves connected to the legs and extending downwardly into individual upper holes extending downwardly into the ocean floor in alignment with lower holes extending further downwardly into the ocean floor: tubular piles, means for supporting said piles in said pile sleeves against downward movement and with portions of said piles extending downwardly into said lower holes, and means for directing the displacement of fluent cement through said piles to the exterior thereof.

10. Apparatus as defined in claim 9, wherein the means for directing displacement of fluent cement through the respective piles comprises a shoe carried by each pile, said shoe having an opening therethrough, and back flow preventing valve means in said opening.

11. In apparatus for anchoring a platform on the ocean floor, the platform having legs engaged with the ocean floor, and a number of pile sleeves connected to the legs and extending downwardly into the ocean floor in alignment with holes extending further downwardly into the ocean floor: tubular piles, means for supporting said piles in said pile sleeves with portions of said piles extending downwardly into said holes, and means for directing the displacement of fluent cement through said piles to the exterior thereof, wherein said means for supporting said respective piles in said pile sleeves comprises anchor means including downwardly holding slips shiftably carried by said pile, means for forcing said slips outwardly into anchoring engagement with said pile sleeve, releasable means normally holding said slips retracted, means 8 for connecting said pile to a running-in string of pipe, and means for effecting release of said releasable means.

12. Apparatus as defined in claim 11, said means for effecting release of said releasable means being responsive to manipulation of said pipe string, said releasable means including shearable means connecting said slips to said pile.

13. In apparatus for anchoring a platform on the ocean floor, the platform having legs engaged with the ocean floor, and a number of pile sleeves connected to the legs and extending downwardly into the ocean floor in alignment with holes extending further downwardly into the ocean floor: tubular piles, means for supporting said piles in said pile sleeves with portions of said piles extending downwardly into said holes, and means for directing the displacement of fluent cement through said piles to the exterior thereof, wherein said means for supporting the respective piles in said pile sleeves includes coengageable abutments on said pile and on said pile sleeve landable one on the other when said pile is lowered in said pile sleeve.

14. In apparatus for anchoring a platform on the ocean floor, the platform having legs engaged with the ocean floor, and a number of pile sleeves connected to the legs and extending downwardly into the ocean floor in alignment with holes extending further downwardly into the ocean floor: tubular piles, means for supporting said piles in said pile sleeves with portions of said piles extending downwardly into said holes, and means for directing the displacement of fluent cement through said piles to the exterior thereof, wherein the means for directing displacement of fluent cement through the respective piles comprises a shoe carried by each pile, said shoe having an opening therethrough, and back flow preventing valve means in said opening, said shoe having means for releasable connection with a running-in string of pipe.

15. In apparatus for anchoring a platform on the ocean floor, the platform having legs engaged with the ocean floor, and a number of pile sleeves connected to the legs and extending downwardly into the ocean floor in alignment with holes extending further downwardly into the ocean floor: tubular piles, means for supporting said piles in said pile sleeves with portions of said piles extending downwardly into said holes, and means for directing the displacement of fluent cement through said piles to the exterior thereof, wherein the means for directing displacement of fluent cement through the respective piles comprises a collar on each pile, sealing means engageable in said pile sleeve, passage means extending through said collar above said sealing means, and back flow preventing valve means in said passage means.

16. In apparatus for anchoring a platform on the ocean floor, the platform having legs engaged with the ocean floor, and a number of pile sleeves connected to the legs and extending downwardly into the ocean fioorin alignment with holes extending further downwardly into the ocean floor: tubular piles, means for supporting said piles in said pile sleeves with portions of said piles extending downwardly into said holes, and means for directing the displacement of fluent cement through said piles to the exterior thereof, wherein the means for directing the displacement of fluent cement through the respective piles comprises a collar on each pile, said collar having sealing means engageable in said pile sleeve, passage means extending through said collar above said sealing means, and back flow preventing valve means in said passage means, said collar having means for sealing engagement with a cement pipe communicating'with said passage means.

17. In the method of anchoring a platform to the ocean floor, the platform having legs extending to the ocean floor and provided with a number of supporting pipes affixed to the legs and disposed in individual holes extending downwardly from the ocean fioor, the wall of each hole surrounding a supporting pipe disposed therein, holes being drilled into the ocean floor below and in alignment with the supporting pipes, the steps of: running 2,345,888 4/1944 Scott 166216 X piles into the supporting pipes and drilled holes on a 3,097,699 7/1963 Orr 166289 X running-in string of pipe, supporting the piles Within the 3,195,646 7/1965 Brown 166216 X outer pipes and drilled holes, placing cement in the a 3,209,544 10/1965 Borrmann 61-46.5 nular spaces between the piles and the walls of the drilled 5 holes, and removing the running-in string. STEPHEN J. NOVOSAD, Primary Examiner References Cited CL XR UNITED STATES PATENTS 166 216 2,075,293 3/1937 Larkin 166--225 X 

